Tools for Nuclear Inspection

Images from commercial satellite and digital monitoring systems are analyzed as part of IAEA inspector operations in Iraq. (Credit: Calma/IAEA)

IAEA nuclear inspectors will have a range of high-tech tools at their disposal as they begin arms inspections in Iraq after a four-year absence. Since 1998, there have been significant improvements in technology they use, mostly software advances that make equipment more powerful and provide faster results.

Among the main tasks for IAEA inspectors will be to throw a detection system, that´s like a net, over Iraq -- a country about the size of France. Its mesh has to contain important evidence from slipping through it. The approach is known as a broad area search. Within a given net, target areas will be selected for closer inspection and fact-finding.

As they gather evidence, inspectors will use a broad array of technologies, such as hand-held radiation detectors and measurement instruments. Some small instruments are used to search for nuclear and radioactive materials known to be associated with weapons-making. Others, known as multi-channel analyzers, can identify specific radioactive elements in samples that inspectors collect for fuller analysis in laboratories.

Analysis of samples can determine "nuclear fingerprints", and reveal indicators of past and current activities in locations handling nuclear materials, particularly those associated with uranium conversion, fabrication, and enrichment. Determining such cases, however, requires expertise and the right equipment -- the fingerprints of different isotopes, for example, can overlap, and an abundant constituent of one element can mask a rare one. Reaching conclusions can be tricky, often requiring multiple dimensional analytical approaches. The IAEA has its own experts and facilities, through its Safeguards Analytical Laboratory in Austria, experienced in sample measurement and analysis, including hundreds of samples from the 1990s Iraq inspections. Fully operational since then is a "Clean Laboratory" equipped with highly sensitive instruments, including electron microscopes and mass spectrometers. Experts can precisely measure even tiny nanogram (one-billionth of a gram) particles and detect traces of nuclear materials collected in the environment of known or suspected nuclear facilities.

Multi-channel analyzers (MCAs). These standard and portable tools for IAEA inspectors register the energy emitted by a radioactive source. MCA´s use software that reads the pattern of the energy output, matches it to a signature, and displays the result. One portable analyzer is designed for detection of gamma radiation from radioisotopes and the presence of neutrons for enhanced detection of plutonium, which is produced in a reactor by irradiating uranium-238. Unlike typical radiation detectors, the device can be used to search for and locate an unknown source of radiation, determine the relative dose rate, and isotopically identify the source. Results are displayed on a digital screen. Uranium and plutonium isotopes, for example, are a good indication of whether nuclear fuel has been reprocessed. Another type, a portable gamma spectrometer, is specifically designed to measure uranium and whether it has been enriched. It can perform accurate and rapid uranium verification measurements in laboratories, at facilities, or in other industrial environments. The ratio of certain isotopes can yield valuable information -- for example, the type of enrichment that was used.

Alloy detectors. Faced with a yard filled with metal objects, the inspectors have use of another portable device, known as ALEX, short for the brand name "alloy expert". Nuclear activities use exotic steels and unusual elements such as zirconium. ALEX allows rapid identification in the field and gives the opportunity to intensify inspections when something important is discovered. For example, UF6 (uranium hexafluoride) is a highly corrosive material used in uranium enrichment. The special alloys required in its production apparatus would be quickly identified by ALEX. Technically, the device is an x-ray fluorescence spectrometer. It generates x-rays to penetrate the material being inspected. ALEX matches the response pattern of elements in the alloy to the x-rays against a library of information in its software and displays the results.

Environmental monitoring instruments. Monitoring water, air and vegetation will form other strands of the search net over Iraq. A nuclear weapons development programme, despite best efforts to conceal it, is likely to leave its fingerprints on nature. Water monitoring will be conducted across Iraq, using a system that draws raw water through a filter for one hour, the equivalent of testing a large volume of water. Laboratory analysis of the filter is able to find the most minute traces of materials in the water with pinpoint accuracy. Air sampling stations will be set up at various points across Iraq and samples of vegetation will be tested for tritium, an isotope of hydrogen. Finding tritium in waterways or the air strongly suggests reactor operations, for example.

Digital video surveillance sytems. Tamper proof and digital video systems are used for surveillance and monitoring at facilities. They could include factories where dual purpose activities could be conducted - for example, the potential use of machine tools to manufacture components for a nuclear programme. Data is fed into powerful computer systems that inspectors use to review and analyze images and related data.

Satellite imagery. For monitoring purposes, images obtained by commercial satellite can help inspectors track activities. A new generation of global satellite positioning (GPS) devices will make it easier for the inspectors to monitor the large country.

Inspection Database. Alongside the full suite of radiation-detection gear and other monitoring equipment, a key tool inspectors rely upon is the Action Team's confidential database. It contains comprehensive and exceptionally detailed information obtained from past inspections, Iraq declarations, defector disclosures, intelligence information, and other multiple sources about Iraq's nuclear-related activities. Inspectors can find out, for example, that a device has been moved from one side of a room to another, and learn why.

The array of tools provide a powerful and complementary package of resources for inspectors that augment their own extensive knowledge and experience. "An inspector could walk into a facility, notice a fresh coat of paint, or a piece of equipment that shouldn't be there, that raises a red flag to the team, " says Jacques Baute, a veteran of the 1990s Iraq inspections and now Head of the IAEA's Iraq Action Team. "Once raised, we're confident we have the means and know-how to find out just what that flag means."

Ultimately, inspections in Iraq ride on factors beyond the inspectors' experience and toolbox. As IAEA Director General Mohamed ElBaradei has emphasized, success will depend on five interrelated prerequisites: (1) immediate and unfettered access to all locations and sites in Iraq and the full use of the authority provided to the inspecting organizations by the Security Council; (2) timely access to all sources of information, including all information available to States; (3) unified and full support by the Security Council throughout the inspection process; (4) the preservation of the integrity and impartiality of the inspection process, free from outside interference; and (5) active co-operation from Iraq, with a sustained demonstration of its stated willingness to be transparent, and to assist the inspecting organizations in fully carrying out their missions.